Grinding machine



Jan. 30, 1923. 1,443,925.

' c. H. NORTON.

GRINDING MACHINE. ORIGINAL HLED JULY3,, I920. i 3 SHEETS-SHEET l.

INVENTOR Ch a rles Il. Noflon J an. 30, 1923.

C. H. NORTON.

GRINDING MACHINE.

ORIGINAL FILED IULYB. 1920.

3 SHEETSSHEET 2.

ATT

BY se INVENTOR Charles H NorTon WITNESS-ES W U- 561cm XKW Jan. 30, 1925.

c. H. NORTON.

I GRINDING MACHINE.

ORIGINAL FILED JULY 3, I920. 3 SHEETS-wSHEET 3.

mii eam s 'LiN figiieon f g zb QWM elk bricating means therefor, and is a division cally and thoronghly,

Patented Jan. 30,1923.

STATES T OFFICE.

CHARLES H. NORTON,

OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTON SETTS.

GRINDING MACHINE.

Original application filed July 3, 1920 Se'ria1 No. 393,913. Divided and this application filed February 28, 1921. Serial No, 448,403.

To all whom it may concern:

Be it known that I, CHARLES H. Non'roN, a citizen of the United States of America, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented certain new and,useful Improvements in Grinding Machines, of which the following is a full, clear, and exact specification. f

My invention relatesto the wheel head. of a grinding machine, and more particularly to a spindle mounting on said head and luof my prior application Serial No. 393,913, filed July 3, 1920, entitled Grinding machines.

One of the greatest difficulties encountered in modern precision grinding machines has been that the wheel spindle which is run at high speed and subjected to high frictional forces is likely to stick either from lack of proper lubrication or on account of the bearings being adjusted too tightly on' the spindle. It is an object of my invention to produce an improved spindle mounting including radial and end thrust bearings for such machines, which will be convenient of adjustment to take up unavoidable wear but -which will prevent the operator from applying excessive pressure to the bearings so as toprevent proper lubrication and cause the spindle to stick. i

It is a further object of my invention to provide an improvedarrangement, self-contained in the wheel slide, for lubricating the grinding wheel spindle bearings automatito insure a continuous, visible and predetermined flow of oil during operation of the machine and to maintain a supply of oil in contact with the spindle at all times.

These objects of the invention, and such others as may hereinafter appear, will be best understood from the following description taken in connection with the accompanying drawings of one embodiment of the invention, in which:

Figure l is a central vertical section of the wheel slide taken through the wheel spindle, looking toward the rear of the machine;

Fig. 2 'is substantially ,a right-hand elevation of the wheel slide, the wheel spindle thrust bearing being shown in section on.

the line 2-2 of Fig. 1;

i Fig. 3 is a section through the thrust bearing on the line 33 of Fig. 2; igqt is an end view of the. wheel spindle thrust'bearing;

5 is a section on the line 5-5 of ig. a F

Fig. 6 is a side elevation of the bearing blgicks and spindle shown in Figsfl and 5; an

Fig. 7 is a fragmentary sectional view taken through the spindle and parts asso ciated therewith on the line 7-7 of Fig. 1.

In the practice of my invention, I employ a wheel slide 1 having parallel V and flat ways 2 and 3 mating with similar ways on the base of the machine, the slide being provided with the usual half nut 4 engaging a cross-feed screw in the base, as is more fully described in my copending application above referred to. The wheel spindle 5'is mounted at right angles to the ways in the adjustable radial and end thrust bearings 6 and 7, which, with the means'fo r supplying oil to the bearings, involveimprovements over a somewhat similar device shown in my Patent No.- 1,191,986 dated July 25, 1916.

In the specific embodiment of my invention selected for illustration, I have shown (Fig. 1) the grinding wheel 10 partially the spindle 5 by suitable flanges 12 and a nut 13. The wheel slide 1 is provided centrally with an opening 14 for the pulley 15 and wheel driving belt 16. The pulley 15 is rigidly mounted on the spindle by means of two conical bushings which are wedged between the pulley and the spindle. g

The bearings 6 on both sides of the pulley are substantially alike, being that the spindle is of larger diameter on one side, hence but one of these hearings will be described in detail. pull of thewheel spindle belt and the thrust exerted by the wheel as it cuts into the'work- 17 having split ends,

the main difference The downward results ina side pressure on the bearing which slants towards the rear or away from the .work at an angle of about 45. In order to receive this thrust in the best possible manner, a semi-cylindrical bearing member 18 (see Figs. 1, 5 and 6) supports. the bottom and back of the shaft and extends or receptacle 20 is formed at the inner edge of the bearing towards which the spindle rotates to hold oil and distributes it throughout the length of the bearing.

.The shaft is held securely seated in this .bearing by two smaller segmental bearing members 21 spaced apart circumferentially from each other and from the fixed bearing member 18 to provide oil channels therebetween and permit expansion. Each of these floating bearing members 21 is preferably made of soft material, such as Babbitt metal, so as to wear away if the bearing is too tight and protect the lower harder bearing block. Each part 21 is provided with a pair of lugs 22 fitting loosely in longitudinal channels formed. between the bearing member of the wheel slide 1 and a cap 23 (see Fig. 5) which is secured to the wheel slide by suitable screws, shown in dotted lines. When this cap is removed, the wheel spindle may be removed from its bearings.

These bearing members are adjustable by fine precision means, which may comprise screws 24 carrying lock nuts, and in order to prevent the operator from putting undue pressure on the bearings and thereby causeing them to stick, these screws are provided with round knurled heads which prohibit the use of the usual wrench and make it diflicult for the operator to set up these screws by any other means than by hand.- The size of the head of the screw is such that if the operator turns them by hand he cannot normally put sufficient pressure on the bearings to cause them to stick. If the operator should purposely find a way of tightening them too much, the spindle would be stopped by the heating and flowing of the babbitt of the frail and narrow blocks but the lower bearing block 18 would not be injured and the machine would be again operable after screws 24 had been loosened.

The floating bearing members 21 are provided with pockets 25 similar to pocket 20 described in connection with the lower fixed bearing member, which, in the case of the lowermost of the two members 21, acts as a pocket or receptacle to hold oil when the machine is standing idle so as to insure sufficient lubrication when it is again started. These bearing members-21 are shorter than the bearing members 18, so that any overflow from the ends of the oil pockets therein will move under the influence of gravity or be carried around by the rotating shaft into the pocket 20 and be distributed therealong.

It is similarly of importance that the end thrust or longitudinal play in a grinding wheel spindle shall be capable of delicate adjustment. 1 Hence, another feature of this invention as claimed in my co-pending application Serial Number 579,031 filed Aug. 1, 1922- contemplates an improvement over the thrust bearing shown in my Patent No. 1,189,861 dated July 4, 1916. Referring particularly to Figs. 1, 2, 3, 4 and 6, itwill be seen that the end of the wheel spindle 5 is provided with an extension having a flange or an equivalent grooved construction adapted to transmit the end thrust to an adjustable member. The specific form illustrated involves a reduced portion 26 which receives a flanged sleeve 27 held rigidly on the shaft by a pair of lock nuts 28. The projecting end of the wheel slide 1 is bored to receive a cap 29 which is attached to the end of the wheel slide hub by suitable screws 30, as shown in Figs. 3

and 4. The inner end of this cap is provided with an inwardly extending flange 31 which takes the thrust of the wheel spindle in one direction. In order to prolong the wearing qualities of the flange 31, it is provided with a hardened steel collar 32 nonrotatably secured to the flange 31 by a pin 33. It will be apparent that this collar 32 provides a rigid abutment to take the thrust of the spindle to the left as shown in Fig. 3.

The thrust of the spindle in the other direction is taken up by a similar hardened steel collar 34 secured by a pin 35 to the end of a cup shaped block 36 which is adjustable toward and fro-m the rigid abutment by means of a screw 37, provided with 'a round knurled head similar to screws 24 and having the usual lock nut, which is threaded into a cover 38 secured to the cap 29 by screws 39. The hardened steel collars 32 and 34 are provided with radial grooves 40 for the passage of oil which is delivered by an oiling system,'hereinafter described, into the interior of the cup shaped block 36 as is indicated by the arrows in Fig. 3. In order to prevent the blo'ck36 from turning in the cap 29, it is provided with a key 41 as shown in Fig. 1. One advantage in this construc- .-tion is that the thrust bearing is not in close proximity toany of the radial bearing members which generate more or less heat during the operation of the machine. Excessive heat in these. parts is liable to cause expansion and a consequent sticking of the thrust bearing. v

The oil reservoir for the wheel spindle is located in the bottom of the wheel slide as is-indicateld at 42, Fig. 1. Oil is taken 'from this reservoir and delivered through pipes 45 and suitable conduits to the bears ings by a pump of the usual centrifugal type as indicated at 46 (Figs. 1 and .2). The pump is driven from the wheel spindle by a chain 47 which receives its power from a suitable s rocket 48 mounted on the wheel spindle. T is sprocket is provided with a conical projection on one side which is received by a tapered opening in one of the conical bushings 17. The other side of the sprocket 48 rests against a shoulder 49 formed on the wheel spindle so that the pressure applied by the other conical bushing '17 in securing the pulley 15 to the wheel spindle also'acts to clamp the sprocket thereon. The pump 46 may be placed in the oil reservoir ,as illustrated. In that case the chain 47 which drives the pump dips into the oil inthe reservoir. In order to prevent an excessive amount of oil being carried up by the chain which, of course, travels at high speed, the portion of the chain which dips below the oil level is enclosed by a dam 50 indicated in Figs. 1 and.

2. It is desirable, however, that some oil shall be applied to the chain; therefore this dam is not made oil tight but there is sufficient leakage ,so that when the machine is standing still the interior of the dam' will fill up with oil, but when the wheel spindle is started running, this oil is soon carriedout by the chain and thereafter sufficient oil will leak into the dam to keep the chain well lu'bricated but not enough to cause an excessive amount to be thrown off when the chain passes around the wheel spindle.

The connection between the pump and" the bearings, as indicated in dotted lines on Figs. 1 and 2, comprises pipes 45 which open into conduits 51 drilled in the" wheel slide 1. The left-hand. conduit 51, shown in Fig.1, delivers oil to the center of the left-hand bearing in the same way that the right hand conduit 51 delivers oil to. the end of the righthand bearing, so that the right-hand bearing oil-delivery mechanism only need be described. -The oil .flows from f.

conduit 51. to a chamber 52 which is provided with a window or sight opening '53 in order that any cessation in the flow of oil may be observed. Fromthis chamber the oil passes bygravity through a conduit 54 into a lon 'tudinal groove 55 which conimunicates with a hole 56 in the block 36 so that a continuous stream of oil is delivered to the interior of the block. The oil passes through the grooves 40 in the hardened' steel collars as has been described,

thereby thoroughly lubricating the thrust bearing, and thence through the interstices between the several members of the radial bearing shown in Fig. 5, dropping into the oil reservoir in the bottom of the wheel slide.

If through any accident the supply of oil should be cut ofl' at the pump, this fact will at once'be evident to the operator as shown by the cessation of the stream of oil flowing back of the window 53. Also, if the passage of the oil through the bearings should be interrupted, it will cause the chamber 52 back of the window to fill'up with oil, which will at once be observed by the operator. By this construction any improper operation of the lubricating system is at once brought to the attention of the operator so that it may be remedied.

In connection with the wheel spindle mounting, there are provided-a number of oil flanges and guards. Between the spindle pulley 15, and the right-hand bearing, as 'shown in. Figs. 1 and 6, there is a-tapered gravity will run down this taper to thev right and then return to the reservoir. This will prevent the=entrance of any oil into the space reserved for the. belt. On the other side of the fbelt pulley, I provide a tapering flange 58 from which oil is thrown centrifugally into the reservoir 42 andagainst the oil guard 59 secured to the wheel slide 46 as by screws (Figs. 1 and 7) and, extending around the upper and forwardportions of the sprocket 48 and flange 58,

from whence it is returned'to the reservoir- 42. The oil guard also catches oil thrown I by chain 47. On the inner wheelflange 12-,

an oil throwing flange 60 is provided to prevent the oil from gaining access to the grinding Wheel.

The operation of the various parts of this device is obvious from the above disclosure. It is also apparent that Iv have provlded a grinding wheel spindle mounting which will serve adequately for heavy productlon grinding or for fine polishlng operatlons.

The bearings, which are adjusted during the operation of the -machine and after they have warmed up may be'maintained in accurate adjustment to insure proper lubrication at all times and prevent sticking of the spindle. The oil should flow steadily during the operation of the machine, hence if a stream is not always visible. in each sight opening, it is a sign that the bearings are not getting theirsupply of oil. However, due to my special construction of thrust and radial bearings'and the oil pass'age's, such a stoppage is unlikely. A large advantage BJI'lSBS from the fac-t'that the oil clrculating pump and reservoir are con- A tained in the wheel slide. No oil is wasted stantly and with the minimum of attention I claim on the part of an unskilled operator who need not be acquainted with the details of construction of the machine.

Having thus described my invention, What as new and desire to secure by Letters Patent is: V

1. In a grinding machine, a grinding wheel slide having a rotatable spindle mounted thereon, bearings for the spindle comprising a lower beari g member adapt-- ed to receive the radial thrust, securing means to fasten said member fixedly on the slide but permit circumferential expansion thereof, floating bearing members separated from one another and said lower member precision means for positioning the bearing members relative to the spindle without permitting'them to be set against the spindle byexcessive pressure.

In a grinding machine, a wheel slide carrying a .rotatably mounted spindle, two fixed and aligning loWerbearing members and fine floating engaging the spindle adjacent its ends and arranged to receive the downward and hori zontal thrusts, two floating bearings cooperating with each fixed bearing, one being vertically andthe other horizontally adjustable in the directions of said thrusts and fine precision means for separately positioning the floating bearings.

relative to the spindle 1 only by manual adjustment. 4O

3. In a grinding machine, a spindle mounted therein, a bearing member for said spindle having an oilpocket for holding an' oil supply in contact with the spindle at all times, an oil reservoir and means for circupocket. I

4. In a grinding machine, a wheel slide having a grinding wheel spindle mounted therein, separated bearing members for said spindle having oil channels therebetween and oil pockets communicating with the channels for holding an oil supply in contact with the spindle at all times, an oil reservoir and oil circulating means comprising -a/ pump for circulating said 011 from the reservoir to the channels and into said pockets.

5. In a grinding/machine, a wheel sl'ide having a grinding wheel spindle mounted therein, separated bearing members for said spindle having oil channels therebetween for holding anoil, supply in contact with the spindle, an oil reservoir to receive the oil flowing ing a conduit above the bearings for pro- Jwith said reservoir,

- thrust bearing and oil channel therebetween re ervoirm id" for feeding oilby gravity operated from the bearings, means comprisa spindle mount thereon comprising rela-- tively adjustable bearing members having a channel for supplying oil in contact with the spindle which overflows into said reservoir, means to adjust the bearing members finely relative to the spindle, means to lift oil from the reservoir to the channel and means permitting the operator to observe the rate of oil flow to the bearings.

' 7. In a grinding machine, a wheel slide having an oil reservoir therein, a grinding. wheel spindle, a driver thereon, a pair of fixed radial bearing members spaced in axial alignment on opposite sides of said driver to support the spindle, an adjustable radial bearing member cooperating with each fixed bearing member, an ad'ustable end thrust bearingmember, means for finely positioning said adjustable members relative to the spindle during rotatio ntheerof, each set of radial bearings having an oil channel adjacent the spindle which communicates an oil conduit to supply gravity feed to said end 'channel' and means to raise oil from said reservoir to said conduit to provide an oil supply for said gravity feed.

8. In a grinding machine, a wheel slide having an oil reservoir therein, a grinding wheel spindle rotatably mounted on said slide, adjustable radial bearing members for the spindle which are separated to form an for holding oil in contact with the spindle, an oil conduit, including a sight opening for observing the rate of oil flow, located above said channel thereto and means by rotation of the spindle to raise oil from said reservoir .to said conduit to provide a-supply of oil for said gravity feed, said channel communicating with the reservoir to return oil thereto.

9. In a grinding machine, a wheelslide having an oil reservoir therein. a fixed radial bearing member above said reservoir, a Wheel spindle mounted thereon, a floating bearing cooperating with and spaced from the fixed bearing member to hold said spindle and provide an oil channel therebetween which communicates with said reservoir, an

oil under a uniform end thrust bearing for the spindle having an oil passage therethrough communicating with said channel, an oil circulating system to supply oil continuously from the reservoir therein, said bearings having oil pockets which maintain a continuous supply of oil in contact with the s indle at all times, an oil reservoir in'sai slide and means to supply oil from said reservoir to a conduit above said pockets and' permit the oil to flow under the action of gravity to the pockets.

11. A grinding machine having a base and ,ways on said base, a grinding wheel slide having slideways on its underside engage ing said ways, bearing members mounted in said slide, a grinding wheel spindle mount- .ed thereon, one bearing member being shorter than the other and spaced therefrom to provide an upper and a lower oil channel therebetween and means'to supply a flow of oil to the upper channel, whereby the oil may overflow around an end of one bearing into the lower channel.

12. In a grinding machine, a wheel slide comprising a housing having an oil reservoir therein, a grinding wheel spindle mounted in the housing, a pulley mounted on the spindle, sets of bearing segments supporting the spindle onvopposite sides of the pulley, each set of segments comprising a lower fixed, bearing member and-upper floating segments spaced apart and from the lower member to provide oil channels, means to supply-oil'from said reservoir to a conduit above the bearings, means providing a gravity flow of oil from said conduit to the bearings and means permitting the operator to observe the rate of oil flow.

13. A grinding machine comprising a wheel slide having a grinding wheel spindle mounted therein, spaced aligned fixed bearing members to receive the'radial thrust of the spindle, a plurality of floating bearing members cooperating with the fixed bearing members to position the spindle, means for manually ad ustin said floating members to, take up for. wear ut preventing the application of excessive pressure, an oil reservoir on said slide, means for circulating oil to said bearingscomprising a pump and conduits leading from said pump to the spaces between said fixed and floating bearing members, and sight-openings in said conduits.

14. A grinding wheel spindle mount comprising a casing, two spaced lower bearing members securing means between said casing and members to hold the latter fixed to the casing in axial alignment and permit expansion thereof, a grinding wheel spindle mounted on the bearing members, a pair of spaced floating bearing members cooperating with and spaced from each lower bearing member to hold the grinding spindle thereagainst, thumb screws cooperating with the casing to independently position said floating bearings accurately against the spindle, and means to circulate oil through the channels between said bearing members and pro- 4 vide a continuous supply thereto.

15. A grinding machine spindle mount com 7 u H prising a casing, a lower bearing member adapted to receive the radial thrust, means to fasten said member on the casing to permit expansion thereof, a wheel spindle mounted in said bearing and a floating bearing member above the spindle and spaced from the fixed bearing member to provide an oil channel therebetwen, said lower bearingmember being provided with an oil pocket in an upper edge which maintains a continuous supply of oil in contact with the spindle at all times. 7 i

16. A spindle mount comprising a casihg having channels therein, a lower bearing block held fixedly in the casing, and arranged to take the downward and rearward thrusts of a spindle thereon, two floating bearing blocks, one arranged above the lower block and the other at the front side, projections on the blocks slidably mounted in said channels and means including thumbnuts for finely adjusting the positions of the blocks tohold the spindle down and rearwardly against the lower fixed block.

.Signed at Worcester, Massachusetts, this 23rd day of Feb. 1921.

CHARLES H. NORTON. 

